I just picked up the Kenai and have it at 282g (9.94oz) on my scale for size Large.
FYI. There was a separate thread about the various Golite fabrics - in this case the Pertex vs. Trinity.
For reference, the weather turned quickly here the other day - pouring rain, 48 deg and about 25mph winds and not a single drop inside the Kenai. I was mostly standing around at a soccer game, so can't comment on breathability. Very nice feature set on the Kenai too.